Chainsaw Repair

I'm surprised at the timing numbers.

8 degrees idle > 16 degrees @ RPM 461 coil
12 degrees fixed with 360 coil.

I've played around with weed whackers and the Homelite 25 was 22 degrees fixed.

I run the Homelite and MacCulloch weed whackers at 28 degrees fixed CD battery ignition with no starting problems but they are small and relatively low compression. I have played with these and moved the timing to see the, under load, results. There is increased RPM under load to increase the timing beyond 22 degrees but beyond 28 degrees the RPM increase falls off to no detectable gain beyond 32 degrees. The setting of these battery powered CD ignitions was done statically with a degree wheel.

I also have some that have been ported and the squish set that run variable timing at about 6 degrees at idle and 28 degrees at about 4500 rpm and above. I also have Echo 50, Dolmar 115, and Red Max 620 engines set up with these numbers. They are all set up to run 7,000 rpm under load.

I thought surely that a 360 would have variable timing?

I also thought that if they were fixed timing that the timing would be 22-25 degrees advance?

I also thought with variable timing curves that the RPM advance would be about 28 degrees?

The Chinese will run 35 degrees at rpm but many people retard the total down to 28 degrees.